1. Technical Field
The present invention relates to a grounding terminal and particularly relates to a grounding terminal which includes a first grounding terminal and a second grounding terminal and in which the first grounding terminal and the second grounding terminal stacked on to each other and locked with each other are fastened and fixed to a connection/fixation target by bolts.
2. Background Art
In FIG. 7, an electric wire 101 is electrically connected to a connection/fixation target typically by use of a terminal fitting 102. The terminal fitting 102 is formed by press working out of a metal plate having electrical conductivity. The terminal fitting 102 includes a terminal body 103 and an electric wire connection portion 104. An insertion hole (not shown) is formed in the terminal body 103. A bolt 105 is inserted into the insertion hole. When the bolt 105 is fastened and fixed to the connection/fixation target, electric connection is completed concurrently. On the other hand, crimping pieces 106 and 107 are formed in the electric wire connection portion 104 continuing to the terminal body 103 formed thus. The crimping pieces 106 and 107 are portions on which crimping is performed. The crimping pieces 106 and 107 are formed so that a conductor exposed portion and an insulator of a terminal of the electric wire 101 can be electrically and mechanically connected and fixed to the crimping pieces 106 and 107 respectively. The typical terminal fitting 102 and its connection have been described above.
For example, in a vehicle such as a car, not The terminal fitting 102 but a special terminal fitting as shown in FIG. 8 and FIG. 9, that is, a grounding terminal 121 is used for grounding connection to a vehicle body (for example, see JP-A-2006-324052). This is because the grounding terminal 121 has a structure in which a plurality of electric wires 122 and 123 can be efficiently connected to a single place. The grounding terminal 121 shown in FIG. 8 and FIG. 9 includes a first grounding terminal 124 which is provided at a terminal of the electric wire 122 and a second grounding terminal 125 which is provided at a terminal of the electric wire 123.
The first grounding terminal 124 has a first grounding terminal body 126 which has a plate-like shape and a first electric wire connection portion 127 which crimps a terminal of the electric wire 122. The second grounding terminal 125 also has a second grounding terminal body 128 which has a plate-like shape and a second electric wire connection portion 129 which crimps a terminal of the electric wire 123. The first grounding terminal body 126 and the second grounding terminal body 128 have a structure as follows. That is, the first grounding terminal body 126 and the second grounding terminal body 128 are stacked on to each other and integrated with each other. The first grounding terminal body 126 and the second grounding terminal body 128 which have been stacked on to each other are fastened and fixed to a body 131 or the like by a bolt 130. Thus, grounding connection is completed.
The structure will be described more specifically. A first bolt hole 132 is formed in the first grounding terminal body 126. In addition, a first lock portion 133 is formed near the first bolt hole 132. In the same manner, a second bolt hole 134 and a second lock portion 135 are formed in the second grounding terminal body 128. When the first grounding terminal body 126 and the second grounding terminal body 128 are stacked on to each other and integrated with each other, the portion corresponding to the first bolt hole 132 and the second bolt hole 134 is formed as a fastening portion 136.
However, there is a fear that the grounding terminal 121 may cause a trouble of terminal detachment due to looseness occurring in the bolt 130. Therefore, the present inventor invented to provide a grounding terminal 143 including two fastening portions 141 and 142 as shown in FIG. 10.
The grounding terminal 143 is designed to include a first grounding terminal 144 and a second grounding terminal 145. The first grounding terminal 144 includes a first grounding terminal body 146 which has a plate-like shape and a first electric wire connection portion 148 which crimps a terminal of an electric wire 147. The second grounding terminal 145 also has a second grounding terminal body 149 which has a plate-like shape and a second electric wire connection portion 151 which crimps a terminal of the electric wire 150. A pair of first bolt holes 152 and 153 are formed in the first grounding terminal body 146. On the other hand, a pair of second bolt holes 154 and 155 are also formed in the second grounding terminal body 149.
The first bolt holes 152 and 153 of the first grounding terminal body 146 and the second bolt holes 154 and 155 of the second grounding terminal body 149 are formed into circular shapes with the same dimensions and at the same positions respectively. In addition, the first bolt holes 152 and 153 and the second bolt holes 154 and 155 are formed in accordance with the size of the shaft portion of each bolt 156. When the first grounding terminal body 146 and the second grounding terminal body 149 are stacked on to each other, two fastening portions 141 and 142 are formed. Two bolts 156 are then inserted and fastened into the first bolt holes 152 and 153 and the second bolt holes 154 and 155 respectively. Thus, grounding connection is completed.
In the grounding terminal 143 configured thus, there is an effect that the grounding function can be kept even if looseness occurs in any one of the two bolts 156.
However, the present inventor found out the following problem in the grounding terminal 143. That is, the present inventor found out a problem that if there are dimensional variations on manufacturing in the first bolt holes 152 and 153 of the first grounding terminal 144, the second bolt holes 154 and 155 of the second grounding terminal 145 and not-shown body-side bolt holes, troubles may occur, for example, in insertion or fastening of the bolts 156 due to the use of the fastening structure using the two bolts 156 so that normal grounding connect cannot be achieved.
Incidentally the present inventor considered that, when lock portions similar to the first lock portion 133 and the second lock portion 135 in FIG. 9 are provided near the first bolt hole 152 in the first grounding terminal 144 and near the second bolt hole 154 in the second grounding terminal 145, The dimensional variations can be absorbed by backlash generated by the lock portions. However, there is a fear that misalignment may occur when the first grounding terminal 144 and the second grounding terminal 145 are stacked on to each other and locked with each other. Thus, the present inventor understood that it is necessary to reconsider the shapes or dimensions of the first bolt holes 152 and 153 and the second bolt holes 154 and 155.
The present invention has been developed in consideration of the circumstances. An object of the invention is to provide a grounding terminal capable of absorbing dimensional variations or misalignment occurring due to various factors so as to achieve normal grounding connection.